Hydraulic remote-control system



March.. 11, 1947. J. B. VAN'DER wERFF 2,417,273

HYDRAULIC EMOTE CONTROL SYSTEM Origixlal Filed June 23. 1942 3 Sheets-Sheet l March l1, 1947.. J B, VAN DER WERFF 2,417,278

HYDRAULIC REMOTE CONTROL SYSTEM original Filed June' 2:5, 1942 s sheetssneet 2 March 11, 1947- JfB. VAN DER wl-:RFF 2,417,278

HYDRAULIC REMOTE ONTROL SYSTEM Original AFled'June 23, 41942 3 Sheets-Sheet 3 i Patented Mar. 11, 19.47 `v i diurno lstares j PATENT orties HYDRAULIC REMOTE-CONTROL SYSTEM Jacob B. -Van Der Werff, Pasadena, Calif., assignor to Adel' Precision Products Corp., a corporation of California OrigiilMpplication June 23, 1942, Serial No. 448,102, novlat'ent No. 2,359,949, dated October 10, 1944.` `Divided and this application i a August 30, 1944, Serial No. 551,932 y 11 claims. l(ci. en -54.5)

This invention has for its primary object the cylinder and movesthe piston in the master unit provision of a hydraulic remote control system` l in the desired directionvand such piston moveby means of which engines and other componentment continues while the lever is being manulmechanisms of aircraft located at points remote ally moved but ceases when the lever is manu from the control cabin or cockpit, may be hy- 5 ally stopped. During the aforesaid movement of draulically controlled withexceptional ease, prethe piston the fluid in the end of the cylinder CiSOIl and dependability regardless f `exfellle toward which the piston is moved is forced into temperatures, severe stresses, relative movement dnd' operates the` vmotor unit piston in oon-oof wing sections and similar factors which here- Spondenco as to direction and extent to the movetofore have caused inaccuracies and failures in l0 'ment of `the master `unil, piston, the fluid roremote eontfel Systems '111 erplenes- The Present turning from the motor unit passing through the application '1S a division of my pending applicamaster unit and into the return side of the systion Sel'. N0. 448,102, filed June 23, 1942, and S- tem nl'oflmyV unit ceases to Operate Sued as Patent, N0. On October 10, 194.4., when master. piston ceases move- Another object of the present invention is the ,l ment, due to the foot `that, the Stopp-mg of manual Pmi/mn 0f a' hydfulc remote contol System movement of the lever causes the master unit to Whefem e master mi and e motor mi are Coneet so that certain of its valves win shut lof: new structed and arranged in such manner that when of. pressure fluid to theV master unit, oylinder the sysfem is not undef Opetatlon the mud hues therefore stopping the movement of the piston extending between said units are under return and the owvof ,return, (operating) vfluid from,

n fluid pressure only and in communication with the fluid reservoir in the System to the end that the master cylinder to the motor unit. Prefer that proper operation of said units will not be soethat the motor unit piston corresponds in l interfered with by. reason ofV expansion and conp .movement to that of the masteruuf. operating, l' f'laion of @he mnd 'under extreme tempera' 25lever' thus aiiording aten-taie indication for vthe benefitof the operator. i p

a eleogt gsggl Hfettlgnclilsagcgv A further important feature of myinventon is that the motor unit is constructed so that it will scribed in which the device or element under f v30 automatically become hydraulically locked when i control is hydraulically locked 1n any position to the flow of operating fluid thereto from the mas .which it is moved and can subsequently be moved ter unit ceases in response to cessation of the f only 1n response to manually initiated opelation manual movement of the master unitoperating ofthe t nifllw b ruli ui.

tion of gxlst' 9 o d y hyd a c Mft' a. lever, thereby providing for the retention yof the v Yet another object of my invention is the pro-l auplane control or component .part Wmcb ,is

` vision of a hydraulic remote control system .n.nder @he .control of the motor mit in the de' wherein the masten and motor umts are antw sired position, regardless of external forces such matically` synchronized when the pistons thereof as Wing and other Stresses Wmd pressure' etc' l are permitted' to reach the limits of their strokes i Another important provismn o f my mvemion in either direction, at which time the uuid win 40 s that the .master and motor mts are deslened be circulated through the entire system to reto Operate nder high pressure 5 that vtheywu move trapped au. and foreign matter aswell as l develop sufficient force to overcome sticking or properly fill the system. other resistance offered the movement of the airlMy invention provides for the objects and adplane parts actuated and controlled thereby re- Van'cogos hereof in a particularly offloaolous 45 sulting from wind pressures, ice formations and manner by reason of the use ofran especially Othel'eeUSeSl M0feOVe1.hS.hEh Pressure dedesigned master unit whereinaplurality of conl sign makes it possibleto use a Smaller.y eOnStruC- trol valves, a hydraulic cylinder having a rey tion and appreciably reduce the weight of the ciprocal Ypiston therein, two fluid lines Ieading v units throughout the hydraulic system.r

,I to the motor unit,and a manually operable lever Another important object of my invention is and associated means for actuating the control to provide a-remof/a control arrangement of 'the valves, are arranged as a small, compact andy character described wherein the' master unit is light-weight unit. When the lever is manipu-l subject to immediate emergency manual operalated to actuate certain of the controlvalves, tion for bringing about the desired operation of pressure uld from the system passes to thethe motor unit in .the event of failure ofthe hy-v -ably the master and motor units are arranged i I `showing in full the pistons of said units at the airplane (not shown) 1to the part or 4device `airfare operate the master unit. l

Another object is to provide a combined closed and open hydraulic .system in which a closed 'system including a hydraulic cylinder transmitter o r master unit is coupled to a hydraulic cylinder receiver or motor 4unit and this closed system is combined with a pump operated or open system which delivers uid under pressureto either'endof the master unit cylinderv so that the piston of the latter will, when moved in either direction responsive to pump pressure, transmit this pump pressure to from the master efiicacious manner.

with the foregoing .'bjects in view,- together with such other objects' and advantages as may subsequently appear, the invention resides in the parte and in the combination, construction and arrangement of parts hereinafter described and claimed, and illustratedv by lway of. example in the accompanying drawings, in which:

Fig. 1 is a schematic view of a hydraulic remote control system embodying my invention, showing the mannerof hydraulically coupling the m'aster -and motor-units and disclosing general construc-v tion and relative arrangement thereof;

Fig, 2 is a schematic lview of the master unit, the full lines indicating a shut-oi position and j the dotted lines indicating how the lever and valves are moved to initiate the operation of the .umn

dotted lines the -when continuing dotted position in figure) to a predetermined advanced point;`

Fig. 4 is a schematic view similar" to Fig. 3 lines the lever and valve mech-- anism as when the manual movement of the lever parts in the position gained is stopped inthe position indicated by the dotted" dotted lines showing the position into which the lever and valve mechanism'are moved by hydraulic -means fol-` lowing .the cessation of manual movement of the` lever.

lines in Fig. 3; the shut-011 Fig. 5 is a schematic view of the system showing strokes as when permitting the liuid to circulate Fig. 3 is a view'similar to Fig. showing in interconnected responsive to movement of the piston the uid in the closed system, thereby operatingthe motor unit solely by means of piston displaced fluid f cylinder, to the endthat the objects and advantages herein recited are attained in a particularly a and return ports E"and F lines H and J from the As hereprovided. the master unit A includes a body member I, said body member, ed on said -body valvular control meansl C in sure from a pump P (diagrammatically shown), e

E, whereas return fluid through a pressure line and return lines E and F are connected tointake section I' of the body I as shown in Fig. 1.

Pressure fluid in the master unit A is employed larmeans G, the operating means D and the lever 4 of thelatter, Fluid forced out of the cylinder by the piston is delivered through one of the two unit B to operate al thereof,the purpose unit piston to move in correspondence to the 'Y movement of the master unit piston .under conto move the lever from the Fig. 1 (full lines in the present ends pf their v ,throughout the, system for synchronizing said e units and removing trapped air,

lever being moved somewhat to the right ofthe full line position thereof shown in Fig. 2;

the operating Fig. 6 is a schematic view of the system as when 3 under manual operation.

One embodiment of my hydraulic control systemas shown in the accompanying drawings,

particularly Fig. 1, generally includes as the i principal parts thereof motor unit B, the master unit being adapted to a master unit A and a cylinder into the trol of the valvularmeans C of thel master unit. Uponmovement of the motor unit piston a drive means K associated therewith becomes operable for controlling or-actuating as desired the airplaneelement or device such as hereinbefore mentioned and which maybe connected drive means in any suitable'manner.

Fluid forced from is returned to the master unit throughA oneof the lines H and J and then passes into themain return line F leading from the master unit'f It is now apparent that the master unit pistonI 3 is actuated by pressure fluid from pump P so that it' will force motor operating medium for the motor kunit piston 6 whereby the drive means K will operate the air- I plane element or device connected to said drive means. Thus the motorunit is operatedby (return) uid pressure, that llld. l I lfizster unit I A passage 8 leads fromt'he pressure fluid port In the vbores I0 and I I are spool-like balanced v valves I2 and I3 respectively adapted to engage be located in the control cabin or cockpit of an I While the motor unit is adjacent and connected to be operated thereby, l such for example, as the throttle of an engine `of the airplane, or the ailerons, vlanding ilaps, engine cowl flaps, or other airplane carried mech- `anism which is subject to hydraulic'actuation.

adapted to be located Inasmuch as the motor u nit may be put Ito the.

above noted and other various uses in aircraft, `and ysuch applications thereof will be readily `understood by those skilled in this art, illustraseats I5 in the respective bores. and I3 are arrangedfto control the iiow of pressure fluid from the bores I 0 and II into cylinder passages I6 and I1 which lead from .the inner ends of bores I0 and lI respectively to opposite ends of the cylinder 2.

Springs I8 hold inasmuch as said valves are balanced' hydraulically by reason of piston-like outer ends I9 the diameter of which is substantially equal to the diameter of said seats.

Each of the valves I2 and I3 has a. passage 20 master unit is adapted I u respectively in a lower master unit to themotor v piston 6 in a` cylinder I being to cause the motor to said v the motor unit'cylinder I-- iiuid from the master unit.V

unit cylinder I as the is. fluid in tinere-` turn sideof thev master cylinder rather than directly bythe pump pressure 55 the body I,.and from The valves I2 the valves I2 and I3 seated.

Hf and J towhich themotorlunit cylinder lines HandJ are connected. Y v f In 'the outer-ends of the,-.bores I0 and -Il are valve members 23 and 24 adapted to seat on the valves I2 and I3 so as to close thepassages 20.

,However, it should be noted thatl inasmuch as the diameter 'of thebodies of .the valve members- 23 and 24 isgrea't'er than that-of the. seats w for the seated ends of said valve'A members, the

' GSpressure of the hydraulic fluid `Will hold said A.valve portions unseated, until' the valve operating vmeans is actuated todepress and seat'said valve members..

In additionv of acting as valves,. the members 23 and 24 operate as push'rods to unseatthe valves I2 and I3 when a `rocker ,member 28, forming part of the operating means D,'is moved from the horizontal position shown in Fig..1 and in full lines in Fig. 2A into thepositions shown .-in full lines in Figs. 4 andv 5 respectively. The rocker member is pivoted as at 29 centrally of its ends onthe body I and operates in a T-shaped chamber 30 the head of whichl opens into the cylinder 2 as shown in Fig. 1. The valve mem bers 2 3 and 24 extend into said chamber as shown in Fig. 1 so that theymay be-` engaged and. operated by tappets 3| `on thel rocker member 28. f l

The valves 23 and 24 lieon opposite sides of the pivot. 29 while beyond these valves and ar-v ranged to be operated -by similar tappets 32 adjacent the ends of. said rocker member are balanced return valves 33 and 34. The valves 33 and 34 operate in bores 38 in the body, at the inner end of which bores are return ports 40 and 4l which lead to a common passage 40 extending `to the return port F to which latterthe main r turn line F of the system is connected.

It should be noted that an inwardly opening spring-loaded check valve C1 is provided in the pressure fluid port E' while an outwardly opening spring-loaded check valve Cz is provided in the return fluid port F'. These check valves cooperate with another spring-loaded check valve C3 which has a weaker spring than the other check valves and controls a port 8 leading between pressure fluid passage 8' and the return fluid passage 40' as shown in Fig. 1, the purpose being to properly control'the flow of fluid during emergency manual operation ofthe system as will be hereinafter' more fully described.

As here provided, the return valves 33 and 34 i are substantially hydraulically balanced .due-'to the diameters of the body portions thereoifand The rocker member 28 (see Figs. 1 and 2) has an ear 43 centrally of its ends and above the pivotv 29 to which'ear the inner end of the operating lever 4 is pivoted as at 44.` The lever 4 is also arranged to be fulcrumed -on the piston 3, as

by means of a pin 45 on said piston and a slot 48 `in the lever. This pin and slot connection makes it possible to manipulate the lever and rockthe rocker 28 in either direction without effecting movement of the piston, yet the piston will effect movement of the lever 'as will be more fully described hereinafter. With reference to Figs. 1 and 2, it is seen i that the piston 3 `comprises aK reduced web or connecting portion 3' joining pistonends 3" and that the lever 4 has. a bifurcated portion 4' mounted astride the web 3' and ear 43, the slot `46 beingl formed in said bifurcated portion. A .l ,slot 41 in the` topof Athe cylinder 2 affords the i `.extension of the lever 4 from the master unit for operation exteriorly thereof. j; l

" As .'ameansjfo'r synchronizing 'the masterand l end of its stroke in either direction, the piston closing check' valves 50 which are adapted to .be -opened by pins .5I mounted in the ends of the cylinder 2. Thus-when Athe piston3 reaches the .end of. its lstroke one of -the `pins 5I will open the check valve Silv contacted-thereby and .the other check valve-wil1 openresponsive to fluid jpressure, thereby opening the passage 49 through the piston. `vA similar arrangement is provided inthe motor unit piston andv and will be hereinafter fully.' described.

Movtorv mit l The motoi-"unit`:s'inoindes s body sa, having ports 54 and 55 to which the-fluid lines H and4 5s to control the nowof fluid through cylinder.l passages 62 and 63 leading'from bore v56 to the ends of the cylinder 1 which is formed.' in the body assembly of the motor unit.

The valves 60 and 6I are arranged to engage I. lseats 65 and are provided with guides 66 on their j valve stems 59. Springs 68 are arranged to urge the valves 60 and 6I toward their seats, also return the piston 58 to neutral position.

Piston members $9 are mounted in ybore 58 i between the valves 60 and 6I are the outer ends of said bore. Springs 1I arearranged to urge these pistons toward the valves and 6I. This bers T in the ends of bore 56, inasmuch as increased pressure resulting from the fluid beso comin-g heated will urge the pistons 69 outwardly and thereby relieve the excess pressure to the atmosphere through vents in the' outer ends of bore 56.

The cylinder I o'f the unit B is provided with pins 'I4 for opening check valves 15 and 16 in the ends of a passage 14 extending through the piston 6.- This-arrangement is the same as hereinbeflre described in connection with the master valve piston 3 andserves as a part of 70 the means for synchronizing the system and removing air trapped therein. Y .The drive-means K as here provided comprises the` piston`6 engaging a drive pinion 1'8 on a.

shaft 80 to which latter a crank arm 8| is I I Y motorunits and circulating fluid .therethrough automatically when the lever 4 is moved'to' the y 3 is providedwith a passage 49 extending axially l. therethrough as shown Ain Figs. 1 and 2, and said `passage is controlled at. its ends by 'outwardly cylinder arrangement provides thermal expansion cham-'- a rack formation 18 on an intermediate part of fixed. This crank yarm provides forfoperatively connecting the motor unit with the airplane part, device or mechanism to be `hydraulically controlled by the vsvstem hereof.

Operation It should be'noted that the norman off position of the operating lever 4 may be different according to different applications or uses of the n system. In some instances, such as when using the system to control ailerons, rudders, etc., which Y arev moved from an intermediate inoperativevor normal position'in either direction into various operative or control positions, y,the lever is set to operate from an intermediate starting position, Vfor example as shown in Fig.A 1. In other instances the lever may be normally disposed in the position shown in full lines in Fig. 2 (inclined to the right) as the starting position. n

. N matter `what the starting position of the Y-lever, the rocker 28 should, be in the level or horizontal position as shown in Fig. 1 and in full lines in Fig.' 2 and the valves of the entireunit in the positions shown in Fig. '1. n

Under' all startingA conditions the spool-like pressure valves I2 and I3 in the master unit are hydraulically balanced by the pressure fluid between the enlarged ends of said valves, the springs I8 holding said valves seated to prevent flow of operating fluid from pump P into the cylinder 2 of the master unit A. Valves 23 and 24, however, are adapted to be opened by pressure of fluid, and valves 33 and 34 are normally held open by means of the tappets 32 on the rocker member 28.

At this time, as no operating iiuid is being j transmitted through the lines H and J`to the mo tor unit, the valves 60 and 6I of said unit (which valves are opened only responsive to the operating pressure from the master unit and movement of piston 58 respectively), are closed and trap the fluid in the motor unit thereby hydraulically lockingysaid unit and holding against movement the airplane part or device operated thereby,

Assuming that the starting position of the lever 4 `is that shown in full lines in Fig. 2, it is seen that when the lever is moved to the left it will fulcrum on its piston-pivot 45v and cause theA lrocker member 28 to shift from horizontal (full line) position, shown in Fig. 2, into the dotted position or inclined position shown in Fig. 2, as l soon as the lever has beenrmoved the extent indicated by the dotted lines to theleft o f said starting position of the lever.' The rocker 28 will remain in this inclined position as longl as the manual movement of the lever is continued. When the rocker 28 is moved into the dotted position shown in Fig. 3 the return valve 33 is 4 allowed to close under influence of its spring 42 as the,tappet 32 at Ithe left end of the rocker is withdrawn from said valve, v and during this yoperation the other return valve 34 is further opened by the other tappet 3 2, while the valve 24 is depressed by one of the tappets 3|, thereby closing passage 20 through the pressure valve I3 and finally opening said presure valve. Valve bore Il for valve I3,-vcylinder passage I1, and

theright end of cylinderV 2 thereby moving the piston -3 to the left.

Y Fluid displaced by-Athe piston from the rleft end of the cylinder 2 is effective toy operate the piston 6 in the motor unit cylinder 'I as follows: passage 'I6',' valve' chamber bore II), passage 2U in valve lI2 therebylifting va1ve'23 and'opening. passage 20 into passage2I.v This pistonl disf placed fluid now flows from port H' into line H to motor unit, valve 60 (opened by the pressure that the shaft so will swingthe crank arm al to y the left for operating the airplane devicefor con-A trol (not shown) which is connected to said crank of fluid entering bore 56), passage 62 andwth'ex.

right end of cylinder 'I. The' piston .6 willibe moved to the left as long as the master plstii 3 Vis moved correspondingly, andto substantially an equal extent. Movement. of the piston .Beto the left operates the rack I8 and pinion1r19d`o arm;

When the valve Gllof the motorunit is opened` by the pressure of the fluid from line H, thepisvton 58 is moved at the same `time tothe left by such pressure fluid and opens the valve 6 I ,'allowl ing fluid nthe left endof the cylinder to flow through passage 63, bore 56, line J to master unit port J into passage 22, thence through the open return valve 34 (valve 24 being now closed), bore 38, return port 4I, passage 40', check Vvalve C21 I .(opened by the pressureof this return fluid), port F' and return line F to reservoir R. -Pressure of the operating iiuid from pumpvP closing valve C3 at this time, is greater than the return fluidv l pressure, whereby valve C3 remainsclosed.

The -foregoing loperation takes .place on the movement o f the lever 4 to the left of any starting position between the ends of itsstroke.

It is now seen ythat thepiston 3 follows thef movement of the lever 4 while the latter is being i moved the extent indicated by -the difference between the full and dotted klinesin Fig. 3;: Con-J4 sequently the piston is moved only by the rireso sure of the fluid from pump P following a prldetermined initial manual movement of the" lever and during lcontinued movement thereof. f

If the operator stops the movement yofgthe lever 4, say in the full line position shown in Fig. 4, the pressure iiuid continues to move the piston 3 While the operatorholds the lever tostop it, and this continued piston movement now` causes thelever to fulcrum at the end heldby the operator andA to assumethe dotted positionV shown in Fig. 4, andin assumingA this positior\ the lever causes the rocker 28 to-swing on its pivot under influence of the piston 3 into the horizontal shut-off positionshown in kdotted lines in Fig. 4

and in4 full lines in Fig. 1,' therebyV permitting valve I3 to close and stopping the -flow of pressure fluid to ythe right end ofy cylinder 2. As soon as pressure fluid is `shut off fromthe right end of cylinder 2 `the piston 3 vstops yand the flow of piston displaced fluid from the left end of cylin f der 2, to the motor unitlceases, thereby allowing f valves and 6I to closeunder influenceof the springs 68.

The uid'isnow trapped in the motor unit and,- 'this part of the system is hydraulically locked'and f serves lto hold the element or device operated' therebyvin the ydesired position against retrograde movement responsive to externally applied forces.

It should be noted that the system willi re- .,main vinoperative until the' lever 4 moved in either direction from the stopped position itI assumes when the valves of the master unit are in the shut-off position as shown in full lines in Figs. 1 and 2.

If the lever 4 is moved to the rightifrom any position thereof in which the Yvalves are in the shut-offr position as shown in full lines inFigs. l

jposition assumed by the rockercontrolledfvalves f 'jlwhen the lever is moved 'initially a short extent i' to the rightfrom any"s tcppe'd position.

Pressure fluid will now ow from the pump P Y through line E. passages 8, 8" and 9 into valve chamber bore I0, cylinder passage I6, 'to the left end of master unit 'cylinder 2 thereby moving the piston 3 tothe right. Fluid from vthe right end of cylinder 2 is forced by piston 3 through passage I1, bore I I, into passage 20 in valve I3 thereby lifting valve 24 so that the flow continues through port J'and line` J to the bore 56 of the motor` unit. Pressure fluid in bore 53 operates to directly open valve 6l and also forces the piston 58 to the right to 'openvalve $0, thereby allowing pressure fluid to flow through passage 63 to the left end of the cylinder 1 and .move piston 6 to the right, while fluid .returns from the right end of the cylinder 1 through open valve 6U, line H to master unit passage 2|, open return valve 33. passages 48 and 40', past check valve C: to line F of the sys-L tem. On stopping the movement of the lever 4, the piston 3 continues to move until the lever 4 is rocked sulcient to move the rocker 28 into the ,level or shut-off position hereinbefore described Pat which time the pressure fluidk isshut off to the hcylinder 2 and the movement of piston 3 ceases. f! vTo synchronize the units and remove trapped Q ir and foreign matter therefrom, the lever is moved to the limit of its stroke in either direction and held there, for example, the position shown in Fig. 5 and the pistons of the master and motor units then move to the limit of their stroke to the right, thereby causing the projections 5I and 14 to unseat the check valves 50 and 15 in the right ends of said pistons of said units while the pressure fluid unseats the `check valves 50 and 16 in the left ends of said pistons.V At this time the rocker28 cannot be moved into shut-off position ber. Valves I3 and34 are closed and valve 24 is.

. y system as`long as the operator holds the lever at the left `(or right) extremity of its stroke. Y

Should 1t become necessary to manually op" erate the `system as in case of emergency, such as upon failure of the pump, or when the pump is shut off for any reason, `the operator moves the handle or lever 4 as the occasion requires, and in sodoing causes themaster unit to actas a pump to force fluid into and operate the motor unit.

When the system is manually operated v'the in'- itial movement of the lever 4 causes the valves of the masterunit to assume the position shown forexample in Fig. 6, before the piston 3 is moved, .in thezsame manner as when' the master unit is hydraulically actuated.v .As soonas this.

small'amount'of ymovementof the leverl relative to'piston 3 is completed, said lever will fulcrum. on its pivotal connection with the rocker mem-l ber 28y as-the'movement thereof continues, thereas the lever is held against the end of slot 41.

With the rocker 28 thus held in positionshown in Fig. 5 the valves34, VI 3 -and 23 are closed While valves 24, I2 an-d33 are opened, and the operating fluid flows as follows; line E past open valve I2, cylinder passage I6, cylinder 21,. check valve at left end of piston 3, passage 49 in piston 3, open valve 50 at right end of piston 3, cylinder.l passage I1, valve bore I I, open/passage 20 in closed valve I3, passage 22 line J pastA valve 87| in thermotor unit opened by the pressure uid, cylinder 1, check valve 1,6 in the left end of motor` unit piston 6` opened by the pressure ofthe fluid, passage 11 in piston 6, open valve 15-at left endof cylinder passage 62, past valve opened-by the piston 58, line H, passage 2| in master unit, open return valve 33; return passages 48 and4' and past c eck valve C2 to the return line F. In this maner the fluid under pump pressure continuesto by moving the piston 3 in the same'directlon (here assumed toward' the left) and forcing fluid into the motor unita'svfollows: from left end of the Cylinder 2 (see Figs. 1 to 4 inclusive) throughr passage I6, bore I0, opened bypressure ofzthe iiuid, and passage 62 to the right end` of cylinder 1 thereby moving motor unit piston 6 to the left and-operating the device orl element of the airplane, which device or element is connected with the lever or crank arm 8| operated responsive to movementof piston 6.

Return fluid news frm the left end` of thev motor unit cylinder 1 throughjpassage B3, past valve 6I which was opened simultaneously with valvet by means of the piston 58, line J to the` master unit, passage 22fvalve 34 thenopen, pas-- sage 4I, passage 40', part 8 past check valveCa which has a` weaker spring than valvesCi and'Cz and opens responslve'to` pressure of the fluid while valves Ci and Cz remain closed, passage 8', branchpassage 9',open valve I3, bore Il, and passage I1 thereby supplying the fluid to the right end 'of master unit cylinder 2. It should-be noted i that during the aforesaid emergency manual operation the-valve Cz remains closed inasmuch as the spring whichI seats said valve is 'stronger` thanthe pressure of the manually displaced fluid. Moreover a vacuum is created inthe cylinder 2 and is effective in the associated passageways'to close valveCz While assisting in theopening of valve C3. vlnasmuch as'the pump of the system 'is not under operation at this time, the check valve C1 will remain closed, while on the other hand the pressure of the manually displaced fluid opens the valve C3 whereby fluid willffiow into theright end of cylinder 2 to `fill vthe increased" space therein as', created upon movement of the. piston to the left. "I'huson the' emergency manualoperation` the fluid is'notreturnedto the return line F as is the case when master unit vpist'or'i 3 is hydraulically actuated. A v

It will be observedthat the two return valves are actuated (one closed and the other further opened)` before the selected pressure valvej( I2 or I3) is opened. and that one of the valves 23 andv 24 is' closed before the selected pressure valve is opened, with any manipulation of thel lever 4from a normal or stopped position. This arrangementinsu'res the best possible results in attaining the objects' and advantages hereinbefre set forth.

lIt is important kto yobserve that When the sys-- tem is Ashut-,off or at rest, the return .valves con;r

trolling .the lines H and J to the motor unit are held open to A allow for relief ofthe fluid under l traction takes place and is effective to induce the,

embodiment of my invention I do not limit my.y l self to the exactv details of construction, set forth, `and' the inventionembraces such changesmodi- "valves for controlling 4the fiowofsaid operating l fluid so thatsaid' piston will behydraulically moved in either direction by Vfluid from' said e 1, source, in correspondence with the movement of 3 said control member; means 4of operative connecf Y tion between said control Amember and said piStOn' l operating-upon cessation'fof the manual movement of said control member to cause the piston l thermal expansion in said lines andthe passages in communication with said lines.'

Incase of contraction of the iluid in the yaforesaid lines H and J and their associated passages, e a smallbleed port C4 as shown in Fig. 1 permits. 5 uid from the return port 3 to by-pass the valve l C2 and enter .said lines and passagesfto'make l up deficiency resulting from the contraction of the lluid.`l AA vacuum is created when the conaforesaid fluid replenishment through the bleed While I have shown and described aspecic iications and equivalents of the parts and their. 1

1 formation and arrangement as vcome withinthe i purview of the appended claims.

.- I claim:

1. In a hydraulic remote control system, a

nected to said source of supply, a vmanually operable control member movable inv opposite directions on said body member, an operating means responsive to said control member for setting said to move said control member and operate said valve operating meansl whereby said valves will shut-off the flow of iiuid vfrom said source to said cylinder and shut ofithe ilow of piston-displaced iluid from said cylinder; a motor unit subject to 1' operation only responsive to the pistonfdisplaced fluidfrom the master unit cylinder. in cludinga g cylinder, a piston inthe motor unitjcylinder, a

drive means operated by said pistonfor actuating a device to beremotely controlled by the system; and hydraulic lines under `control of certain of l `said Vvalves for conducting piston-displacedY fluid l fromthe master unit cylinder to the motor unit cylinderand operating .the motor unit piston, also for conducting to said return'passage the fluid displaced vbv the `motor unit piston.

2; In a hydraulic remote control system, a master unit including a body member, a cylinder'associ'ated with said body member, a piston recip- ,f rocable in said cylinder, ar source of supply of iluidrunder pressure, valves and related fluid pasl sages in said body member for controlling the flow I i oilriyfdraulic operating iluid from said source of l supply to the endsoi'v said cylinder and the flow offluid displaced lfrom the 'ends of said Cylinderv i by the pistoma iluid return passage in said body member. c'onnected'to said'source Yof supply of 1 operating iluid, a manually operabley control i membermovable in opposite directions on said body member, a valve operating means which is responsive to saidcontrol member for settingsaid.

v connection with'the device ormechanism whichv in either direction by fluid from said source, upon f the manual movement of said controlmember; a motor unit responsive to fluid delivered thereto from the master unit cylinder; hydraulic fluid lines under control of saidV valvesvfor conductingl piston-displaced iluid froml the master unit cyl...` inderto the motor` unit as wellas forconducting';` the iluid displace'dzfrom the motor unit to said.

ment of said control member.' 3. In a hydraulic remote controlsystem, a master unit including'a cylinder, a reciprocable piston in said cylinder, -a manually operable control member movable in opposite directions',"}a motor" unit including a cylinder;areciprocable piston in said motor unit cylinder, a'hydraulic pump, a,

reservoir for the pump, an operating fluid yinlet v and a yreturn fluid outlet in said master unit confvv nected with said pump, iluid passageways for connecting said .operating uid inletfwith thefends of the master unit cylinder foroperating the master unit piston in either directiomiuid lines connected with said fluid passageways for supplying piston-displaced fluid vfrom the master unit cylinder to the motor unit' cylinder, and forreturning the fluid displaced by the pisto'n'inthe motor unit cylinder to vsaid return duid outlet and .thence to the reservoir,valves arranged for. controllingthe flow of pump fluid" to either end of the master unit cylinder and the Vflow of said. piston-displaced fluid from` the otherfend of said master unit cylinder; valve operating 'meansre' sponsive tomovement of said control member for controlling said valves to selectively supply oper. L r'ating iluid from the pump to either end of 'said master unit cylinder as well as selectivelyv supplyf piston'displacediluid from either end ofthe mas" ter unit cylinder to the complementary end the motor' cylinder unit, also ycontrol the flow of fluid displaced by the motor yunit piston; to' said return fluid outlet for return to said reservoir,

4. Ina hydraulic remote control system, a mas- `ter unit including a hydraulic cylinder .having a reciprocable piston therein; a motor unitpfor is to be lremotely controlled Yby'jthe system;4 a hydraulic pump, a reservoir 'for the pump, fluid vlines connecting-said pump with said masterunit and saidmaster unit with said motor unit, and manually operable valvular means in the master unit for-'selectively controllingthe flow ofy operatl ing fluid `from said" pump'to either end ofl'said masterunit cylinder, as well-as the llow of pistondisplaced fluid from said master unit cylinder to the rcomplementary end vvof the motor, uniti and..V l l also for controlling the'ilow of-return fluid from the motor unit cylinder to vsaid reservoir and said master unit cylinder.v v

5. In a hydraulic remote control system, a master unit including a body member, a cylinder asl sociatedwith said body member, a piston in said cylinder, a pump, a reservoir-forv the pump, valves e and related passages in said body member for conf trolling the ilow of hydraulic operating iluidfrom Said pump to the ends of said cylinder, alsothe flow of piston-displaced fluid from said cylinder,` l

afluid return passage in'said body member conu nected to said reservoir and to ends of said cylinder, a manually operable control'member movable l valves toV control the flow of said operating uid 3 so that said piston will be hydraulically moved 75 Jmeans whereby said valves will shut ofi the iiow of iiuid to and from said cylinder; a motor unit `subject to operation responsive to the pistondisplaced fluid from the master unit cylinder; lhydraulie lines under control of certain'of `said valves for conducting 'piston-displaced lluid from the master unit cylinder and operating the motor unit, also for conducting to said return passage the fluid returned from the motor unit; the aforesaid means of operative connection between the manually operable control member and the master unit piston providing for emergency manual operation l' the master unit piston to force operating fluid from either end of said cylinder to the motor unit responsive to manual movement of said control member, certain of said valves operating responsive to said manual operation of the master unit to shut oil flow of return iluid to said reservoir and open the return passage to communication with an end of said cylinder.

6. In a hydraulic/'remote control system, a fluid reservoir, a duid pump connected to the reservoir, a master unit including-a cylinder and a piston reclprocable therein, a motor unit for actuation responsive to said master unit, iluid lines 'connecting said pump and reservoir with opposite ends oi' said cylinder, other fluid lines arranged Y \to deliver piston-displaced fluid from either end of said cylinder to said motor unit for operating the latter in either direction, valve .means selecively operable for routing fluid from the pump o either end of the cylinder while directing pison-displaced fluid from the other end of the cylinder to said motor unit and at the same time routing return fluid from said motor unit to said reservoir: and control means for operating said valve mean-s.

7. In a hydraulic remote control system, a fluid reservoir, a uid pump'connected to the reservoir, a master unit including a cylinder and a piston reciprocable therein, a motor unit for actuation responsive tosaid master unit iluid lines connecting said pump and reservoir with opposite ends of saidcylinder, other fluid lines arranged .f

to deliver piston-dispaced fluid from either end of said cylinder to said motor unit for operating the latter in either direction, valve means selectivelv operable for routing iiuid from the pump to either end of the cylinder while directing piston-displaced fluid from the other end of the vcylinder to said motor unit and at the same time routing return uid from said motor unit to said reservoir; and control means for operating said valve means, and means associated with said control means and operable when the control means is manually moved while the pump is shut oil, to move said piston so as to deliver iluid from either end of the cylinder to the complementary end, said motor unit, and other valve means responding to the last named operation of said control means so that uid returned from said motor unit is delivered to said cylinder instead of to said reservoir.

8. In a hydraulic control system a iluid reservoir, a uid pump connected to the reservoir, a

master unit, including a cylinder andA a piston reciprocable therein, a motor unit, iiuid lines connecting said pump and reservoir to opposite ends of said cylinder, other fluid lines arranged lto connect opposite ends ci said cylinder to said motor unit, valve means selectivelyA operable to route iiuid from the pump to either end of said f cylinder While also directing piston-displaced fluid from said cylinder to the complementary end of said motor unit tooperate the latter in either direction and simultaneously routing fluid returned from said motor unit into said reservoir, and control means for operating said valves and including a connection with said piston such that when the pump is shut ofi said control means may be manually operated to move the piston in either direction for forcing fluid into and operating said motor unit, and valve means responding to said control means to direct return uid from said motor unit into said cylinder instead of into v said reservoir.

9. In a hydraulic remote control apparatus, a fluid reservoir, a fluid pump connected to vthe reservoir, a primary reciprocal unit constructed and arranged to respond to hydraulic pressure from said pump and by such response to transmit ,V

a hydraulic torce in a reverse direction to operate a secondary reciprocal unit, means connecting said secondary unit in series with said primary unit, and manual'control means including valves constructed and arranged to be selectively operated by said control means and upon operation to admit pressure fluid from the pump to operate the primary unit in either direction, and simultaneously to direct iiuid discharged from said primary unit to said secondaryvunit for operating the latter in either direction while also directing return iiuid trom the secondary unit to said reservoir.

10. In a hydraulic remote control apparatus, a fluid reservoir, a fluid pump connected thereto, a hydraulic motor unit adapted to be connected to an element or mechanism to be controlled, a primary reciprocal operating unit, means hydraulically connecting said motor unit in series with said primary unit, said primary unit being constructed and arranged to respond to hydraulic pressure from said pump for operation in either direction and by such response to transmit a hydraulic operating force to said motor unit to opern ate the latter in either direction, and manually operable control means including valves and constructed and arranged so that when operated will admit fluid to the primary unit to operate it in either direction while directing fluid from said primary unit for operating the motor unit in ether direction and at the same time routing uid from said'motor unit to said reservoir.

11. In a hydraulic remote controlapparatus, a fluid reservoir, a uid pump connectedthereto a hydraulic motor unit adapted to beconnected to an element or mechanism to belcontrolled, a primary reciprocal operatingun'it, means hydraulically connecting said unit in series, said primary v instead of to -said reservor.

JACOB B. VAN DER WERJE'F".V

L16 REFERENCES CITED The following references are of record-in the le of this patent:

` Number l10 Number UNITED STATES' PATENTS Name Date Y vWheelon -.v.`l --v. Aug. 11, lil-.12 n i EQBEIGN PATENTS I Country Date British T Feb.} 14, 1939 feste 

